The present invention relates to a suspension system for a vehicle and more particularly to a suspension for an independent drive axle.
Conventional vehicle suspension systems that are cooperative with the drive axle utilize coil springs and complex control linkages in order to protect the drive axle output. This has been standard construction so that no forces are transmitted back to the differential and its accompanying transmission. Further, when a vehicle is braked on a vehicle having independent suspensions that are coupled to the drive shaft, there is a problem of maintaining vehicle control due to the unusual forces imparted to the wheel axle. U.S. Pat. No. 3,770,291 to Kramer discloses a torsion suspension system employing three torsion springs, two of which are connected directly to a drive axle housing wherein the forces reacting on the wheel will impart their stresses and force reactions to the drive axle and the universal joint as well as the differential. Further, forces on one wheel are transmitted to the other wheel. The present invention provides an independent suspension system that utilizes a torsion spring operative with the drive shaft wherein the suspension system absorbs all forces from the wheel which would otherwise be transferred through the drive shaft to the differential. The present invention further provides a compact unit that eliminates bulky struts and extraneous tie rods for the system with no requirement for lubrication. Such suspension system is particularly advantageous in that it requires a minimum of ground clearance thereby permitting a lower center of gravity for the vehicle which is very important as in the case of motor homes. A modification of the invention employs a torsion spring system that provides a simplified independent system that is also maintenance free and also requires no lubrication.